import cv2
import numpy as np

image = cv2.imread('kele.jpg')

hsv = cv2.cvtColor(
    image,
    cv2.COLOR_BGR2HSV
)

lower_blue = np.array([100, 100, 100])
upper_blue = np.array([140, 255, 255])
blue_mask = cv2.inRange(hsv, lower_blue, upper_blue)

red_color = [0, 0, 255]
image[blue_mask > 0] = red_color


cv2.imshow('kekou', image)
cv2.imwrite('kele1.jpg',image)
cv2.waitKey(0)